JP2022504891A - Stretched aromatic polyether - Google Patents

Abstract

An aromatic polyether-based stretched filament obtained by stretching the filament at a temperature between the glass transition temperature and the melting point and cooling the filament to a temperature lower than the glass transition temperature under a total tensile load, a method for producing the same, and its use. ..
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Description

The present invention relates to an aromatic polyether-based drawn filament obtained by stretching the filament at a temperature between the glass transition temperature and the melting point and cooling the filament to room temperature with full load.

Fiber reinforced materials are usually based on the use of glass or carbon fiber as the polymer. This means that there is a fundamental problem with the compatibility of the fiber with the matrix material, that is, there is a problem with the adhesion between the reinforcing material and the matrix. This is often a significant problem when using thermoplastics as a matrix. Moreover, these materials are very difficult to separate from the fibers and cannot be recycled.

The prior art discloses two main methods of stretching polyolefins such as polyethylene and polypropylene, a melt spinning method (Patent Document 1) and a gel spinning method (Patent Document 2). Polyolefins can be easily stretched at room temperature, but it is necessary to select a relatively slow stretching rate due to the heat generation during stretching. Stretched polyolefins have the disadvantage that when treated at high temperatures, they shrink very significantly after stretching, so they must first be equilibrated at the desired working temperature. Moreover, stretched polyolefins have very limited mechanical value that determines their usefulness as reinforcing fibers. In particular, the lack of thermal stability and the lack of compressive stress (cold formability) are drawbacks.

Non-Patent Document 1 reports an ultrafine PEEK filament obtained by a melt spinning method, which is obtained by reducing the mass throughput per spinneret and at the same time increasing the take-up speed.

Non-Patent Document 2 discloses a stretched PEEK filament. However, this type of PEEK filament has insufficient mechanical properties (see Example 4).

Patent Document 3 discloses ductile fibers of various thermoplastics (preferably polypropylene and polyethylene) as components of so-called prepregs. These are understood to mean the weave of thermoplastic and brittle fibers (especially carbon fibers). These materials are preferably thermoformed or compressed in a matrix of ductile fiber materials. This melts the ductile fibers and improves the adhesion between the matrix and the brittle fibers.

Poly (p-phenylene terephthalamide) (PPTA, aramid of the following brand names: Kevlar (registered trademark) (trademark of DuPont in the United States), Twaron (registered trademark) (trademark of Teijin Lim in Japan)), etc. The production of fully aromatic polyamide fibers is described in Patent Document 4.

In the context of the present specification, the term "filament" is understood to mean a fiber, film, or ribbon. In particular, the film is preferably stretched in a plurality of directions.
The term "stretching" is understood to mean the drawing process performed at the end of extrusion by the application of thermal and mechanical energy.

International Publication No. 2004/028803A1 International Publication No. 2010/057982A1 International Publication No. 2013/190149A1 U.S. Patent Publication No. 3,869,430A

Brunning et al. (J Mat Sci 38 (2003) pp. 2149-53) Shekar et al. (Journal of Applied Polymer Science, Vol. 112, No. 4, pp. 2497-2510)

Therefore, the problem to be solved by the present invention has been to provide a method for producing drawn filaments from aromatic thermoplastics, and a method for drawing aromatic thermoplastics that is harmless, simple and requires no solvent. ..

This problem was solved by a stretched filament of aromatic polyether, which was cooled at full load after stretching.

The present invention comprises at least 80% by weight, preferably 85% by weight, more preferably 90% by weight, even more preferably 95% by weight of aromatic polyether, particularly preferably containing only aromatic polyether and filament. Provided is a stretched filament obtained by stretching the filament at a temperature between the glass transition temperature and the melting point and cooling the filament to a temperature lower than the glass transition temperature at full load.

In the context of the present specification, the temperature between the glass transition temperature and the melting point at which the filament is stretched is also referred to as "stretching temperature". This temperature is maintained during the stretching operation in a manner known to those of skill in the art.

The present invention further provides a method for producing a drawn filament according to the present invention.

The invention further provides the use of drawn filaments according to the invention for the manufacture of composite materials.

The invention further provides the use of drawn filaments according to the invention for producing winding layers.

One of the advantages of drawn filaments according to the invention is that they hardly shrink at high temperatures, i.e., they have little relaxation effect.
The drawn filament according to the present invention also has an advantage of high mechanical stability. Mechanical stability is preferably measured in the form of fracture stress in the stretching direction.
The drawn filament according to the present invention also has an advantage of high mechanical stability even at high temperatures.

The drawn filaments according to the invention, surprisingly, exhibit the above advantages over prior art. Despite much analytical effort, the inventors have been unable to find parameters that provide a physical explanation for these advances.

The stretched filaments according to the present invention, the composite materials according to the present invention including the filaments according to the present invention, and the manufacture and use thereof according to the present invention are described below without intending that the present invention is limited to the following exemplary embodiments. Will be described as an example. When a range, general formula, or group of compounds is specified below, these are all obtained by excluding individual values (ranges) or compounds, as well as the corresponding range or group of compounds explicitly mentioned. Includes a partial range and a group of partial compounds. Where the literature is cited within the context of the present specification, the entire content is intended to form part of the disclosure of the present invention. When the numerical values are shown as percentages below, these are the numerical values in% by weight unless otherwise specified. In the case of a composition, the percentage value is a value for the entire composition unless otherwise specified. When the average values are shown below, they are mass averages (weight averages) unless otherwise specified. When the measured values are shown below, unless otherwise specified, these measured values are values measured at a pressure of 1013.25 hPa and a temperature of 25 ° C. The melting temperature and the glass transition temperature were measured by DSC in accordance with EN ISO 11357-1: 2016D. The glass transition temperature is sometimes referred to as glass temperature in the art.

The technical details and embodiments presented in connection with one aspect of the invention are not expressly excluded and are also applicable to other aspects where technically possible. For example, embodiments and preferred parameters of drawn filaments according to the invention are applicable to the methods according to the invention with the necessary modifications and vice versa.

The scope of protection includes the commercial finished products and packages themselves of the products according to the invention, as well as any reduced form, to the extent not defined in the claims.

According to the present invention, the filament is stretched at a temperature between the glass transition temperature and the melting point and then cooled to a temperature below the glass transition temperature at full load.

The aromatic polyether is preferably polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone etherketoneketone (PEKEKK), polyetherketoneketone (PEKK), polysulfone (PSU), and polyethersulfone. (PES), polyarylsulfone (PAS), and mixtures and copolymers thereof. More preferable aromatic polyethers are polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone etherketoneketone (PEKEKK), and polyetherketoneketone (PEKK).
The aromatic polyether preferably contains no solvent.

The filament according to the present invention is preferably drawn with a draw coefficient (SF) of 5 or more, more preferably 10 or more. Stretching coefficients in the context of the present specification are understood to mean coefficients due to filament length increased after stretching. For example, when the starting filament having a length of 1 m is stretched to 10 m after stretching, it is stretched with a stretching coefficient of 10.

The filament according to the invention is preferably stretched in free space without contact. The area where the stretching is performed is an area where the environmental atmosphere is heated, that is, a kind of tube furnace or a space between two heating plates.

The filaments according to the invention can be stretched continuously or in batch.
Static stretching, that is, a stretching operation in which one end of the filament is kept at a speed of 10 mm / min to a maximum of 200 mm / min, preferably 20 mm / min to a maximum of 100 mm / min, and more preferably 30 mm / min to 80 mm / min is preferable.

The preferred continuous stretching operation preferably has a low transfer rate of 5 mm / min to a maximum of 20000 mm / min, more preferably 10 mm / min to a maximum of 3,000 mm / min, and even more preferably 50 mm / min to a maximum of 2,500 mm / min. Minutes, and even more preferably in the range of 100 mm / min to a maximum of 2,000 mm / min, particularly preferably 500 mm / min to 1,500 mm / min. The stretch factor is used to calculate the speed of the transport unit operating at higher speeds. For example, the transport speed can be adjusted by adjusting the operating speed of at least one roll or spool at the start and end of the filament to be stretched, respectively.

The filament according to the present invention can be stretched by only one stretching operation or continuously multiple times. In the latter case, the selected stretching temperature needs to be higher. A one-time stretching operation is more preferable.

After the stretching operation, the filament according to the present invention is cooled to less than 130 ° C., preferably less than 120 ° C., more preferably less than 110 ° C., even more preferably less than 100 ° C., particularly preferably less than 90 ° C., particularly preferably less than 80 ° C. It is preferable to be done.

The filament according to the present invention is cooled to a temperature lower than the glass transition temperature after the stretching operation. This cooling is preferably carried out gradually, preferably over at least 10 seconds, more preferably at least 20 seconds, even more preferably at least 30 seconds, even more preferably at least 45 seconds, particularly preferably at least 1 minute.

The filament according to the invention is cooled under full tensile load. In the context of the present specification, this means that at least 80% of the stretching force continues to act on the filament during cooling. The tensile force is preferably 90%, more preferably 95%. Even more preferably, the tensile force is substantially the same as the tensile force during stretching. Ideally, the tensile forces are the same.

It is preferable that the drawn filament according to the present invention shrinks / relaxes only slightly in the tension direction when heated to a temperature lower than the melting point.

Preferably, the relaxation temperature is higher than the glass transition temperature and lower than the melting temperature, preferably lower than the stretching temperature.

The filament according to the invention relaxes up to 6%, preferably up to 5.5%, more preferably up to 5%, even more preferably up to 4.5%, particularly preferably up to 4%, with respect to the stretch length. do.

The relaxation of the filament according to the present invention is preferably unaffected under tensile stress.

The drawn filament according to the present invention preferably has a length of more than 5 times the length in the direction perpendicular to the longitudinal direction thereof. The filament is preferably a so-called endless filament. The length of the filament is always measured in the direction of tension.

The term "filament" in the context of this specification is understood to mean a fiber, film, or ribbon. In particular, the film is preferably stretched in a plurality of directions.
The preferred filament is a ribbon. Ribbons with a width to thickness ratio of 7 to 150, preferably 8 to 100, are preferred.

Individual filaments can be processed to form composites. Thus, preferred composites with fibers are fiber bundles and yarns, the fiber bundles or yarns can be processed to make additional composites, preferably unidirectional or multidirectional scrims, mats and knits. Weaves such as, or mixed products can be made.

The scrim may consist of, for example, either a filament cut to a specific length or an endless filament wrapped around a tube.

A preferred scrim composed of endless filaments is a layer wrapped around a hollow body. In this case, the filament is preferably a ribbon. The winding layer is preferably unidirectional or multidirectional, more preferably unidirectional. The multi-directional winding layer has an angle with respect to the tensile direction of the filament. This angle is preferably in the range of 5 ° to 120 °, more preferably 30 ° to 90 °, and particularly preferably 15 ° to 80 °. For winding layers around the tube, these windings have an angle of inclination with respect to the center of the tube. It is preferred that different winding layers have different tilt angles. The winding layer around the tube is preferably designed with respect to the tilt angle so that the edges of the layers are flush with each other after rotation.

In a further aspect, the invention relates to a method for producing filaments stretched according to the invention.
The invention also comprises at least 80% by weight of aromatic polyether and is obtained by stretching the filament at a temperature between the glass transition temperature and the melting point and then cooling to below the glass transition temperature under full load. The present invention relates to a method for producing a drawn filament, particularly a filament drawn according to the present invention.

Some experimental examples are particularly preferred parameters of the method according to the invention and are described below. For example, as described above, the stretch coefficient is preferably 5 or more, more preferably 10 or more. Stretching is preferably done statically.
Further, the cooling is preferably performed for at least 10 seconds, preferably at least 20 seconds, more preferably at least 30 seconds, particularly preferably at least 45 seconds, and particularly preferably at least 1 minute.
After stretching, the filament may be cooled to less than 130 ° C, preferably less than 120 ° C, more preferably less than 110 ° C, even more preferably less than 100 ° C, particularly preferably less than 90 ° C, particularly preferably less than 80 ° C. preferable.
The method according to the invention preferably has only one stretching operation.

The method according to the invention advantageously produces drawn filaments that, when heated to a temperature below the melting point, shrink / relax only slightly in the tensile direction, preferably less than 6% of the stretch length. Enables.

Advantageously, the filaments according to the invention are notable in terms of higher stretchability, which cannot be achieved by prior art methods. On the other hand, prior art filaments tend to shrink unnecessarily after stretching (especially after relaxation) in connection with the loss of mechanical properties. Therefore, advantageously, the method according to the invention makes it possible to provide drawn filaments without, for example, at high temperatures, with significantly less unwanted shrinkage, as compared to known prior art methods. ..

In a further aspect, the invention relates to a tube comprising a winding ply containing at least one drawn filament according to the invention. These tubes are noteworthy in terms of exceptional stability.

material:
PEEK: VESTAKEEP® 5000G, Evonik trademark Melt temperature and glass transition temperature measurements at 20 K / min heating rate, according to DIN EN ISO 11357-1: 2016D, automatic peak recognition and integration. This was done using a equipped PerkinElmer diamond meter.

Experimental Example 1 Preparation of test piece:
In either case, PEEK is extruded with an extruder (Collin E45M) at a temperature of 390 ° C, calendered to produce a ribbon with a thickness of 650 μm and a width of 23 mm, and cooled to 130 ° C to obtain one test piece. Made.
The pick-up speed was 1.4 m / min.

Experimental Example 2 Static or continuous stretching of the test piece:
Method 1 (static stretching):
In a tensile tester (Zwick, Z101-K), the test piece according to Experimental Example 1 was stretched at a rate of 10 mm / min at 200 ° C. Before releasing the tensile stress, the stretched test piece was cooled to room temperature. As a result, a drawn filament according to the present invention was obtained.
Method 2 (continuous stretching):
The seamless test piece according to Experimental Example 1 was placed on the spool. Each test piece is subjected to a continuous machine (Retech Drawing) at a material supply speed of 4 rpm (corresponding to a transport speed of 1,000 mm / min) and a tensile speed of up to 32 rpm (corresponding to a transport speed of 8,000 mm / min). , Stretched to a maximum stretch factor (SF) of 8. If the draw factor was low, the tensile speed was adjusted accordingly. Stretching was performed at a temperature of 200 ° C. The stretched test piece was cooled to room temperature before releasing the tensile force. As a result, a drawn filament according to the present invention was obtained.

Experimental Example 3 Mechanical test by tensile test:
A dumbbell test piece (test piece) according to DIN 527-5: 1997 was punched out from the drawn filaments obtained by Method 1 and Method 2. The thickness was the result of each stretching experiment and was not changed.
Tensile strength was measured at 23 ° C. at a test speed of 5 mm / min, a clamp length of 120 mm, and a measurement length of a 75 mm increment gauge using a Zwick tensile tester. The relative humidity was 50%.
The results are reported in Tables 1 to 3. Each result is an arithmetic mean of tensile tests of three dumbbell test pieces, each made from one drawn filament.
In Tables 1 to 3, the "maximum strength" indicates the maximum force (substantially the breaking strength) before breaking or tearing the dumbbell test piece.
Table 1: Results of tensile test using Experimental Example 3 (static stretching) at a temperature of 23 ° C.

Table 2: Results of tensile test using Experimental Example 3 (continuous stretching) at a temperature of 23 ° C.

Experimental Example 4 (Comparative Example)
Similar to Method 2 of Experimental Example 2, the test piece obtained according to Experimental Example 1 was stretched at a material supply rate of 4 rpm at 200 ° C. As mentioned above, the tensile speed was matched to the desired draw factor.
Unlike Experimental Example 2, the stretched test piece was immediately cooled without a tensile load.
Table 3: Results of tensile test according to Experimental Example 4 at a temperature of 23 ° C.

As described in Experimental Example 3, dumbbell test pieces were punched out and their mechanical properties were measured by a tensile test.

Stretching and cooling under tensile loads clearly improved the mechanical properties of the filaments according to the invention. In contrast, the mechanical properties of filaments produced by non-inventive methods (Table 3) were far inferior to the corresponding filaments according to the invention (Tables 1 and 2) with comparable stretchability. The elastic modulus of the stretched filament of the comparative example was actually inferior to that of the unstretched comparative sample when stretched to a coefficient of 2, for example. The improvement at higher draw coefficients was also much less noticeable than in the case of comparable filaments according to the invention.

A particularly disadvantageous feature pointed out by the present inventors was that the filament produced according to Experimental Example 4 without using the method of the present invention showed high shrinkage after cooling. As a result, reproducible mechanical properties could not be realized. This is a further drawback of the filaments according to the prior art as compared to the filaments according to the invention.

In addition, experiments have shown that static stretching has significantly better mechanical properties than continuous stretching.

Claims (19)

A stretched filament containing at least 80% by weight of an aromatic polyether and obtained by stretching the filament at a temperature between the glass transition temperature and the melting point and cooling the filament to below the glass transition temperature under full load. The stretching element according to claim 1, wherein the melting temperature and the glass transition temperature are measured by DSC in accordance with EN ISO 11357-1: 2016D. The aromatic polyether includes polyetheretherketone (PEEK), polyetherketone (PEK), polyetherketone etherketoneketone (PEKEKK), polyetherketoneketone (PEKK), polysulfone (PSU), and polyethersulfone (PES). ), Polyarylsulfone (PAS), and mixtures and copolymers thereof, according to claim 1 or 2. Any one of claims 1 to 3, which comprises 85% by weight, more preferably 90% by weight, even more preferably 95% by weight of the aromatic polyether, and particularly preferably containing only the aromatic polyether. The stretching element described. The stretching element according to any one of claims 1 to 4, wherein the filament is a fiber, a film, or a ribbon. The stretching element according to claim 5, wherein the filament is a ribbon. The method for producing a drawn filament according to any one of claims 1 to 6. A method for producing a drawn filament containing at least 80% by weight of an aromatic polyether, wherein the filament is stretched at a temperature between the glass transition temperature and the melting point and then cooled below the glass transition temperature under full load. 7. The method of claim 7 or 8, wherein the melting temperature and the glass transition temperature are measured by DSC in accordance with EN ISO 11357-1: 2016D. The method according to any one of claims 7 to 9, wherein the stretching step is performed by a static method. The method according to any one of claims 7 to 10, wherein the cooling is carried out for at least 10 seconds, preferably at least 20 seconds, more preferably at least 30 seconds, particularly preferably at least 45 seconds, particularly preferably at least 1 minute. After stretching, the filament is cooled to less than 130 ° C, preferably less than 120 ° C, more preferably less than 110 ° C, even more preferably less than 100 ° C, particularly preferably less than 90 ° C, and particularly preferably less than 80 ° C. The method according to any one of items 7 to 11. The method according to any one of claims 7 to 12, wherein the stretch coefficient is 5 or more, more preferably 10 or more. The method according to any one of claims 7 to 13, wherein the stretching operation is performed only once. A filament produced by the method according to any one of claims 7 to 14. Use of the drawn filament according to any one of claims 1 to 6 or 15, for producing a composite material. Use of the drawn filament according to any one of claims 1 to 6 or 15, for manufacturing a winding ply. A wound ply or composite material comprising at least one stretched filament according to any one of claims 1 to 6 or 15. A tube containing at least one winding ply containing at least one stretched filament according to any one of claims 1 to 6 or 15.